Method of transmitting/receiving LTE system information in a wireless communication system

ABSTRACT

In a wireless mobile communications system, the system information is grouped or classified in different types according to the characteristics of the system information, and the system information is transmitted to channels with specific functions that allow the optimization of the resource usage and the reception by the User Equipment (UE).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a reissue application of U.S. Pat. No. 8,538,444,issued on Aug. 28, 2013 and based on U.S. patent application Ser. No.12/293,805, filed on Sep. 19, 2008, which is the National Stage filingunder 35 U.S.C. 371 of International Application No. PCT/KR2007/001335,filed on Mar. 19, 2007, which claims the benefit of U.S. ProvisionalApplication Ser. No. 60/784,680, filed on Mar. 21, 2006, the contents ofwhich are all hereby incorporated by reference herein in their entirety.

DISCLOSURE OF INVENTION Technical Solution

This disclosure relates to a wireless communication system, moreparticularly, to a method of transmitting/receiving LTE systeminformation in a wireless communication system.

In the related art, the system information is mainly broadcasted througha channel [i.e., P-CCPCH channel] having a constant data rate in theUniversal Mobile Telecommunications System (UMTS). This implies that thetransmission of system information has static characteristic. When thesystem information is transmitted through the fixed radio resources, thenetwork cannot have flexibility for scheduling of data transmission sothat it becomes hard to be applicable to the change of radioenvironment. As such, the transmission of system information is notcoordinated between different cells. Therefore, in the case of OFDM,using only one static channel for the transmission of system informationwould not allow to optimize the transmission or reception of the systeminformation.

This disclosure has been developed in order to solve the above describedproblems of the related art. As a result, this disclosure provides amethod of transmitting and/or receiving the system information on anOFDM air interface in an efficient manner.

Accordingly, this disclosure is directed to a method of transmittingand/or receiving the system information in a mobile communication systemthat substantially obviates one or more problems due to limitations anddisadvantages of the related art.

To implement at least the above feature in whole or in parts, thisdisclosure may provide a method of broadcasting or receiving the systeminformation in a mobile communication system, the system information isgrouped or classified in different types according to thecharacteristics of the system information, and then the systeminformation is transmitted or received via different types of channelswith specific functions that allow the optimization of the resourceusage and the reception by the User Equipment (UE), wherein thedifferent types of channels may be a statically scheduled channel and/ora flexibly scheduled channel.

Additional features of this disclosure will be set forth in part in thedescription which follows and in part will become apparent to thosehaving ordinary skill in the art upon examination of the following ormay be learned from practice of this disclosure. The objectives andother advantages of this disclosure may be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

FIG. 1 is an exemplary diagram illustrating protocol architecture of theE-UTRAN.

FIG. 2 shows an exemplary structure of an OFDM transmission.

FIG. 3 shows an exemplary structure of an OFDM subframe structure.

FIG. 4 shows an exemplary diagram illustrating sub-carriers intransmission bandwidth.

FIG. 5 shows an exemplary diagram illustrating a reception of severalcells by a UE.

FIG. 6 shows an exemplary diagram illustrating 10 MHz UE in 20 MHzspectrum in accordance with a present disclosure.

FIG. 7 shows an exemplary diagram illustrating a reception of the BCH inthe case of 20 MHz system bandwidth in accordance with a presentdisclosure.

FIG. 8 shows an exemplary diagram illustrating a primary and a secondaryBCH in accordance with a present disclosure.

One aspect of this disclosure is the recognition by the presentinventors regarding the problems and drawbacks of the related artdescribed above and explained in more detail hereafter. Based upon suchrecognition, the features of this disclosure have been developed.

Although this disclosure is shown to be implemented in a mobilecommunication system, such as a UMTS developed under 3GPPspecifications, this disclosure can also be applied to othercommunication systems operating in conformity with different standardsand specifications.

FIG. 1 is a block diagram of a network structure of an E-UMTS(Evolved-Universal Mobile Telecommunications System) to which technicalfeatures of this disclosure may be applied. Recently, an initiative hasbeen started in the scope of the 3GPP (3^(rd) Generation PartnershipProject). project to standardize a new air interface for a mobilecommunication system compared to the second generation air interface (asknown under the name of GSM based on TDM (Time division multiplexing)and FDM (Frequency division multiplexing)), and the 3^(rd) generationair interface (as known under the name UMTS and based on CDMA (Codedivision multiplexing)). The new air interface that is currentlydiscussed as LTE (Long Term Evolution) is based on OFDM (OrthogonalFrequency Division Multiplexing). The E-UMTS is a system evolving fromthe conventional UMTS and its basic standardization is currently handledby the 3GPP.

Referring to FIG. 1, an E-UMTS network includes a user equipment(hereinafter abbreviated ‘UE’), a base station (hereinafter named ‘eNodeB’ or ‘eNB’) and an access gateway (hereinafter abbreviated ‘aGW’)connected to an external network by being located at an end of theE-UMTS network. The eNB and the aGW are connected via an interfacecalled S1. The aGW may be classified into a part for handling usertraffic and a part for handling control traffic. A first aGW forprocessing new user traffic may communicate with a second AGW forprocessing control traffic via a new interface. A first interface fortransmitting user traffic or a second interface for transmitting controltraffic may be located between several eNBs. Here, the eNB may includeat least one cell.

The eNB may perform functions of selection for Access gateway (AGW), arouting toward the AGW during a Radio Resource Control (RRC) activation,a scheduling and transmitting of paging messages, a scheduling andtransmitting of Broadcast Channel (BCCH) information, a dynamicallocation of resources to UEs in both a uplink and a downlink, aconfiguration and provision of eNB measurements, a radio bearer control,a radio admission control (RAC), and a connection mobility control inLTE_ACTIVE state.

The functions located in the eNB will be briefly described as follows:the function of ‘Inter Cell RRM’ may handle the use of the availableresources between different cells and eNBs. The function of ‘Connectionand Mobility Control’ may control the maintenance of the connectionbetween the network and a relocation of the UE context in case ofmobility. The function of ‘RB Control’ may maintain radio bearers (RBs)between the UE and the eNB. The radio bearer (RB) is a service providedby the second layer (L2) for data transmission between the terminal andthe UTRAN. In general, the setting of the RB refers to the process ofstipulating the characteristics of a protocol layer and a channelrequired for providing a specific data service, and setting therespective detailed parameters and operation methods. The function of‘Radio Admission Control’ may provide for services with specific Qualityof Service (QoS) requirements to ensure the availability of certainresources. As such, it may be necessary to decide for a requested radioservice, when the required resources are available and the admissionwould not endanger the availability of resources for already admittedservices. The function of ‘eNB Measurement Configuration and Provision’may provide the eNB to configure measurements in the UE and to provideit with information for performing these measurements. The function of‘Dynamic Resource Allocation’ may provide the eNB to allocate theavailable resources dynamically for the different UEs which are servedby the eNB. The radio resource control (RRC) layer may be located at thelowest portion of the third layer (L3) is only defined in the controlplane and may control logical channels, transport channels and thephysical channels in relation to the configuration, reconfiguration, andrelease or cancellation of the radio bearers (RBs). Additionally the RRCmay handle user mobility within the RAN, and additional services, e.g.location services. The RLC layer may perform segmentation, concatenationin sequence delivery, repetition, error recovery and other functions inorder to exchange Service Data Units (SDUs) between the eNB an the UEentity. The RLC layer may create Protocol Data Units (PDUs) that use asequence number in order to allow the re-ordering, and the detection oflost or re-transmitted PDUs. The MAC layer may control the access to thetransmission resources. The physical layer may provide an informationtransfer service to an upper layer by using various radio transmissiontechniques.

In the E-UTRAN, the AGW may perform functions of a paging origination, aLTE-IDLE state management, a ciphering of the user plane, supporting aPacket Data Convergence Protocol (PDCP) function, a System ArchitectureEvolution (SAE) bearer control, and a ciphering and integrity protectionof Non-Access Stratum (NAS) signalling.

The functions located in the aGW will be briefly described as follows:the function of ‘SAE Bearer Control’ may provide the UTRAN to constructand to maintain a radio access bearer (RAB) for communication betweenthe terminal and the core network. The core network may requestend-to-end quality of service (QoS) requirements from the RAB, and theRAB may support the QoS requirements the core network has set. As such,by constructing and maintaining the RAB, the UTRAN may satisfy theend-to-end QoS requirements. The function of ‘The Mobility ManagementEntity’ may handle access data from the home database, and may maintainsubscription data (e.g. allowed areas, etc.), may accept/deny UEslocation in IDLE, may store UEs location (TA) in IDLE, may handle useridentity confidentiality (TMSI) and so on. The Packed Data ConvergenceProtocol (PDCP) layer may be located above the RLC layer. The PDCP layermay be used to transmit network protocol data, such as the IPv4 or IPv6,efficiently on a radio interface with a relatively small bandwidth. ThePDCP layer may reduce unnecessary control information used in a wirednetwork, and may perform a function called header compression. Inaddition the PDCP layer may provide ciphering and integrity protectionfor the transmitted data.

Transport channels may be introduced in the wireless communicationssystem in order to allow different types of quality of service for thetransmission of information. The transport channel may provide a serviceto the MAC layer and may connect to the physical layer. The differenttransport channels may be introduced in the LTE as followings: first,types of downlink transport channels can be described as follows; 1.Broadcast Channel (BCH) is characterised by: a) fixed, pre-definedtransport format, and b) requirement to be broadcast in the entirecoverage area of the cell 2. Downlink Shared Channel (DL-SCH) ischaracterised by: a) support for HARQ, b) support for dynamic linkadaptation by varying the modulation, coding and transmit power, c)possibility to be broadcast in the entire cell, d) possibility to usebeamforming, e) support for both dynamic and semi-static resourceallocation, support for UE discontinuous reception (DRX) to enable UEpower saving, and g) support for MBMS transmission (FFS) 3. PagingChannel (PCH) is characterised by: a) support for UE discontinuousreception (DRX) to enable UE power saving (DRX cycle is indicated by thenetwork to the UE), b) requirement to be broadcast in the entirecoverage area of the cell, and c) mapped to physical resources which canbe used dynamically also for traffic or other control channels, and 4.Multicast Channel (MCH) is characterised by: a) requirement to bebroadcast in the entire coverage area of the cell, b) support forcombining of MBMS transmission on multiple cells (the exact combiningscheme is FFS), and c) support for semi-static resource allocation(e.g., with a time frame of a long cyclic prefix). Also, types of uplinktransport channels can be described as follows; 1. Uplink Shared Channel(UL-SCH) characterised by: a) possibility to use beam-forming; b)support for dynamic link adaptation by varying the transmit power andpotentially modulation and coding, c) support for HARQ, and d) supportfor both dynamic and semi-static resource allocation and 2. RandomAccess Channel(s) (RACH) is used normally for initial access to a cell,and the RACH is characterised by: a) limited data field, and b)collision risk.

The UEs may receive system information before the UE (i.e., terminal)accesses a cell in a mobile communication system. This systeminformation may contain information that is used by the UEs in an Idlestate (i.e. when no context exists between the UE and the eNB) and in aconnected state. For exemplary purpose only, the main system informationmay be sent on the BCCH logical channel which is mapped on the P-CCPCH(primary Common Control Physical Channel). Also, specific systeminformation blocks may be sent on the FACH channel. When the systeminformation is sent on FACH, the UE may receive the configuration of theFACH either on the BCCH that is received on P-CCPCH or on a dedicatedchannel. Here, the P-CCPCH may be sent using the same scrambling code asthe P-CPICH (primary common pilot channel) which is the primaryscrambling code of the cell. The spreading code that is used by theP-CCPCH may have a fixed SF (spreading factor) of 256 and the spreadingcode number may be one. The UE may know about the primary scramblingcode either by information sent from the network on system informationof neighboring cells that the UE has read (i.e., by messages that the UEhas received on the DCCH channel) or by searching for the P-CPICH (whichis always sent using the fixed SF 256 and the spreading code number 0with a fixed pattern).

The system information may include information on neighboring cells,configuration of the RACH (Random Access Channel) and FACH (ForwardAccess Channel) transport channels, and the configuration of MICH (MBMSIndicator Channel) and MCCH (Multicast Control Channel) which arechannels that are dedicated channels for the MBMS (MultimediaBroadcast/Multicast Service) service. It may be camping (in idle mode)whenever the UE changes the cell, or the UE may need to verify whetherit has valid system information when the UE has selected the cell (inCELL_FACH, CELL_PCH or URA_PCH state). The system information may beorganized in SIBs (system information blocks), a MIB (Master informationblock) and scheduling blocks. The MIB may be sent very frequently andmay give or provide timing information of the scheduling blocks and thedifferent SIBs. For SIBs that are linked to a value tag, the MIB maycontain information on the last version of a part of the SIBs. The SIBsmay be linked to an expiration timer if the SIBs are not linked to avalue tag. Here, if the time of the last reading of the SIB is biggerthan this timer value, the SIBs linked to an expiration timer may becomeinvalid and may need to be reread. Also, the SIB s linked to a value tagmay be valid if they have the same value tag as the one broadcast in theMIB. Each block may include an area scope of validity (i.e., Cell,Public Land Mobile Network (PLMN), equivalent PLMN) which signifies onwhich cells the SIB is valid. For example, a SIB with area scope “Cell”may be valid only for the cell in which it has been read. A SIB witharea scope “PLMN” may be valid in the whole PLMN. A SIB with the areascope “equivalent PLMN” may be valid in the whole PLMN and equivalentPLMN.

The UEs may read the system information when they are in idle mode,CELL_FACH state, CELL_PCH state or in URA_PCH state of the cells (i.e.,cell that the UE has selected, cell that the UE is camping on). The UEsmay receive information of neighboring cells on the same frequency,different frequencies and different RAT (Radio access technologies). Bydoing this, the UE may know which cells are candidate for cellreselection. In a CELL_DCH state, the UE may know about the differentradio links other than the UE currently use. In this case, it mayincrease the complexity for the UE to read additional channels such asthe BCCH channels. Therefore the information of neighboring cells may bereceived in a dedicated message from the RNC, and only for some veryspecific functions. However, it may be possible that UEs read systeminformation sent on the P-CCPCH channel or other transport channels inthe CELL_DCH state.

The LTE (Long Term Evolution) may be based on OFDM (Orthogonal FrequencyDivision Multiplexing). FIG. 2 shows an exemplary transmitter of an OFDMscheme.

As illustrated in the FIG. 2, an input signal (symbols) may be modulatedusing a QAM modulation. The stream of modulated signal may be convertedin a parallel complex bit-stream. Then, the bit-stream may be passedthrough a Discrete Fourier conversion block. After the mapping of thebits to the relevant frequencies, a vector may be fed into the InverseFast Fourier transmission block. Here, the parallel to serial conversionblock may create a complex signal. A cyclic prefix may be added to thesymbol in order to handle a multi-path transmission. The output signalafter each IFFT may be called an OFDM symbol.

Several OFDM symbols may be grouped together in order to form asub-frame as illustrated in FIG. 3. The high bit-rate stream may beconverted in several parallel bit-rate streams with lower data rate.Thus, each stream uses a smaller bandwidth and each stream is morerobust for a frequency selective fading and multi-paths. Here, as longas the sub-carriers are transmitted with the same sub-carrier spacing,it may be possible that the UE receives only parts of the completetransmission bandwidth as shown in FIG. 4. (i.e., shaded and un-shadedparts show the sub-carriers that are transmitted, and the shaded partshows the sub carriers that are only received). Thus, the bandwidth forreception and transmission may be differently used.

The LTE system may be designed such that it can operate in manydifferent bandwidths (e.g. 20 MHz, 10 MHz, 5 MHz, 2.5 MHz, and 1.25MHz). Thus, the UE may not know about the bandwidth used by a cell whena UE attempts to find out the existence of a cell. The UE may transmit areference signal, which can be transmitted through a Synchronizationchannel (SCH), in order to allow the UE to find out the existence of thecell. Here, the reference signal may be transmitted on the SCH using apart of the total bandwidth in order to allow the UE to discover anycell. Therefore, the UE may only need to search for a limited number ofSCH bandwidths.

Also, the UE may determine the existence of a cell and may acquiresub-frame synchronization by searching for the SCH channel. In order toallow the UE to receive more information on the cell characteristics, itmay be necessary for the UE to receive broadcast information which iscarried on the BCH channel. Such a BCH channel may be transmitted on alimited or part of the total bandwidth just like in the case of the SCHchannel.

In a multi-cell environment, the UE may receive different signals(cells) permanently from several base stations. In this case, thetransmission of the different signals may be not synchronized when theUE decodes the transmission of one cell (e.g. the transmission of signalof a cell B may create interference with a cell A, and may increase theprobability of false reception by the cell A). In order to increase theprobability of correct reception, the cells may transmit the same signalin a time aligned manner with a coordination of their transmission, suchthat the UE may jointly decode the received signal from both cells asshown in FIG. 5. This type of reception manner can be called softcombining because the UE may combine the received signal of both cellsduring the reception phase. The signals of the different cells are notperceived as interference, and thus soft combining may increase thequality of the signal received by the UE. Although many other differenttechniques may exist for the soft combining, this scheme may require avery strict or tight synchronization between the cells. When the OFDM isused as a modulation scheme, the time synchronization may need to be inthe order of a length of a cyclic prefix in order to handle aconstructive interference.

A selective combining may be used if a tight level of synchronization isnot possible. The selective combining method can be discriminated to thesoft combining, as the selective combining method allows the UE toreceive the signals sent from several base stations independently.Although the two cells may not transmit the same signal, the UE may knowthat the two cells transmit the same data. Thus, by receiving thetransmission of signals of both cells, it may be possible to receivedata (i.e., RLC PDUs) correctly from one cell even though other data hasnot been correctly received by another cell. As such, the selectivecombining method may increase the overall quality of the data reception[i.e., faster transmission]. Because the selective combining may beperformed at RLC level, RLC sequence numbers may be used in order tore-order the Protocol Data Units (PDUs) received from the differentcells involved in the selective combining.

Due to the fact that a global downlink capacity [i.e., bandwidth] of acell is bigger or larger than the reception capacity of the UE, thebandwidth of the UE may not be utilized or used for a maximum downlinkbandwidth. (i.e., only part of total downlink bandwidth is used)Usually, the maximum bandwidth for a cell is set to 20 MHz in the LTEsystem, and the UE's minimum reception bandwidth is set to 10 MHz. Thus,the UE with 10 MHz receiver may tune its receiver to a leftmost or arightmost part of the spectrum as shown in FIG. 6. Therefore, data orsignals on the BCH or the SCH may not be correctly received if such dataor signals are transmitted on a center frequency of the downlinkbandwidth.

This disclosure may provide a method or system such that the systeminformation is grouped or classified in different types according to thecharacteristics of the system information, and the system informationmay be sent on channels with specific functions to allow theoptimization of the resource usage and the improved reception by the UE.Here, the system information may be grouped in primary systeminformation and secondary system information as shown in Table 1. Theprimary system information may be composed of information that isessential for further reception of the secondary system information. Thesecondary system information may be further devised in cell-level systeminformation and PLMN-level system information, depending on whether acontent of the information is a cell specific [i.e., information is onlyvalid in a specific cell] or same content for different cells of samePLMN [i.e., information is valid in the entire network]. Also, sometypes of system information may change frequently due to the radiocommunication environment, while other types of system information donot change as frequently. As such, the Cell-level system information maybe further devised in dynamic information and semi-static systeminformation depending on whether the content of the information changesfrequently (dynamic) or not frequently (semi-static).

TABLE 1 Different types of system information Primary System InformationSecondary System Cell-level Semi-static Information Dynamic PLMN-level

Here, the primary system information may be sent on a transport channelwith fixed scheduling, such as the BCH, whereas the secondary systeminformation may be transmitted on a transport channel with flexiblescheduling, such as DL-SCH. The PLMN-level system information may betransmitted with a coordination of neighboring cells such that theselective combining or the soft combining can be applied. The BCH may betransmitted in a way that the UEs can receive a rightmost, leftmost, orcenter part of a total downlink bandwidth (i.e., 20 MHz spectrum) if theUEs have a capability to receive only limited bandwidths (i.e. 10 MHz).

The system information may be categorized in detail, as shown in Table2.

TABLE 2 Different types of system information Primary System InformationPLMN information (e.g. MIB) Scheduling information of BCCH blocks, i.e.Secondary system information blocks (e.g. R6 MIB or SB) Secondary Cell-Semi- Cell selection/re-selection information System level static (e.g.R6 SIB3) Information Semi-static common channel information (e.g. R6SIB5/6) Measurement control information (e.g. R6 SIB11/12) Cell-levelLocation Service information (e.g. R6 SIB15 except SIB15.3) Informationon PLMN identities of neighbouring cells (e.g. SIB18) Dynamic Dynamiccommon channel information (e.g. R6 SIB7, SIB14, SIB17) PLMN-level NASsystem information (e.g. R6 SIB1) Information on UE timers/counters(e.g. R6 SIB1) PLMN-level Location Service information (e.g. R6 SIB15.3)Pre-defined Configurations (e.g. R6 SIB16)

When a UE is located or camped on a cell, the UE may read the primarysystem information of the Table 2 immediately after a synchronizationprocess by synchronization channel. The primary system Information mayhave a cell specific and semi-static characteristic. The primary systeminformation may contain scheduling information of the secondary systeminformation blocks. (e.g., R6 MIB or SB) Thus, after reading the primarysystem information, the UE can read the secondary system informationblock on a scheduled time and frequency. The cell-level secondary systeminformation of the Table 2 is grouped as the cell-specific. Therefore,when the UE moves to a new cell (i.e., different than current cell), theUE may read the cell-level secondary system information in the new cellregardless of reading of the cell-level secondary system information ofa previous cell.

The dynamic cell-level secondary system information of the Table 2 mayinclude fast changing parameters such as interference. It may be usedfor a common channel such as Random Access Channel (RACH). Here, exceptfor the dynamic cell-level secondary system Information, all of thecell-level secondary system information of the Table 2 may be consideredas semi-static. (i.e., content is not frequently changed) The PLMN-levelsecondary system information of Table 2 may be not cell-specific, butcommon to multiple cells in PLMN area. Thus, if the UE, which has readthe PLMN-level secondary system information in a previous cell moves toa new cell and the PLMN-level secondary system information has not beenmodified, the UE may not need to read the same PLMN-level secondarysystem information in a new cell. Here, the PLMN-level secondary systeminformation usually has semi-static characteristic.

For the system information in a LTE system, a MIB may use a fixedresource because the UE may not presumably acquire any controlinformation before receiving the MIB in a cell. However, eNB canschedule SIBs (i.e., SIBs on SCH) within a specific Transmission TimeIntervals (TTI) indicated by the MIB. If a certain SIB is scheduledwithin a certain TTI, control information of the TTI may indicateexistence of a SIB in the TTI and may schedule a time or frequency ofthe SIB. As such, the eNB may have more flexible size of the SIB withina range of minimum UE capability. Also, the eNB may have moreflexibility of SCH scheduling. In details, the UE may receive the MIB atthe fixed downlink (DL) resource (e.g. time/code/frequency). If the MIBincludes long-term scheduling information of SIB transmissions and theUE has a specific SIB, the UE may receive a DL control channel for oneor more TTIs indicated by the long-term scheduling information of theSIB in order to acquire a short-term scheduling of the SIB. And then, ifthe UE find that the short-term scheduling information at the TTI on theDL control channel indicates the existence of the SIB in this TTI andthe UE successfully receives the short-term scheduling information ofthe SIB, the UE may receive the SIB at the DL resource on a DL broadcastchannel (e.g. time and frequency of the DL broadcast channel) indicatedby the short-term scheduling of the SIB. Afterwards, UE may operatebased on the received SIB.

The BCH channel may have a globally fixed configuration for UEs todecode without any control information. Thus, the primary systeminformation may be broadcast on the BCH. Here, the secondary systeminformation may be broadcasted on DL SCH. In this case, a configurationof the DL SCH on a BCCH may be carried on the primary system informationon the BCH. A second layer (L2) may be able to differently handletransmissions of primary and secondary system information (e.g.segmentation/concatenation). Therefore, different BCCH logical channelsmay be configured for primary and secondary system information. As seenin the Table 2, a SIB1, a SIB15.3 and a SIB16 may across several cellsin the PLMN area. Here, the SIB1 may contain NAS system information anda UE timer/counter, SIB15.3 Location Service information and SIB16pre-defined configurations. In LTE system, when the SIB1 and SIB16 arebroadcasted on the BCCH, combining techniques across several cells maybe considered to transfer NAS system information, UE timer/counter andpre-defined configurations.

Usually, a soft combining may be considered better than a selectivecombining in terms of performance. Therefore, the soft combining may beapplied to the PLMN-level system information like SIB1 and SIB 16 in aLTE system. As such, a first layer (L1) may provide a specific commonpilot and long cyclic prefix for the SIB1 and SIB16. In addition, asynchronous time and/or frequency transmission of the specific systeminformation between cells may need to be provided. Alternatively, theselective combining may be applied to the PLMN-level system informationlike SIB1 and SIB16 in the LTE system. Here, the first layer (L1) maynot need to consider the specific common pilots, the length of cyclicprefix and synchronous transmissions. However, a UE should decodemultiple cells to selectively combine BCCH channels of multiple cells.Moreover, the UE should apply duplication avoidance function in a secondlayer (L2). For this duplication avoidance function, an aGW may need toprovide sequence numbers of the PLMN-level system information.

The special case of 20 MHz system bandwidth where a UE is receiving onepart of the carriers is shown in FIG. 7. As illustrated in FIG. 7, theUE, which is allocated to a right half of a bandwidth, may not able toreceive a BCH correctly in the case that the BCH is coded and positionedon a center frequency. Thus, in order to allow that the UE can receivethe BCH in all cases, the BCH should be transmitted in a differentmanner. Here, an alternative 1 or an alternative 2 may be proposed. Inthe alternative 1, the BCH blocks may move toward the upper 10 MHz orthe lower 10 MHz, as shown in FIG. 7. In alternative 2, the BCH may besplit in two blocks that can be received independently. In this case,the UE may be tuned to receive both blocks, as the UE may receive halfof the BCH transmissions and receive the other half part of the BCHtransmission. Therefore, the UE may still be able to receive the BCH,although this UE may not receive the BCH as fast as other UEs.

Here, system information may be split in primary system information andsecondary system information, as BCH should be transmitted in the sameway for different system bandwidths. The primary system information maycomprise a system bandwidth, scheduling information of secondary systeminformation and other basic information (e.g. the MIB in R99). Theprimary system information may be transmitted as described above on theBCH channel (which could also be called a primary BCH). The Primary BCHchannel may have a fixed configuration. (i.e., depending on theconfiguration of the SCH) The secondary system information may compriseother system information blocks, and the second system information maybe transmitted on a secondary BCH or a DL-SCH. Here, theses channels mayhave a flexible configuration that every UE can support with minimum UEcapability. It may be possible that the configuration may be provided onthe primary system information. If a cell supports a bandwidth widerthan 1.25 MHz, the secondary system information may be sent on widerbandwidth than 1.25 MHz, or up to the minimum UE receiver bandwidth.Thus, the secondary system information may be transmitted at anysubcarrier and time based on the scheduling information contained in theprimary system information.

This disclosure may provides a method of broadcasting system informationin a mobile communication system, the method comprising: classifying thesystem information based on characteristics of the system information;and transmitting the classified system information via at least one of afirst type of channel and a second type of channel, wherein the firsttype of channel is a statically scheduled channel and the second type ofchannel is a flexibly scheduled channel, wherein the first and secondtype of channels are transport channels, the system information may beclassified into primary system information and secondary systeminformation, the primary system information includes at least one ofPublic Land Mobile Network (PLMN) information and scheduling informationof the secondary system information, the system information isclassified into cell-level system information and PLMN-level systeminformation, the system information is the cell-level system informationwhen a content of the system information is used or valid to a specificcell, the system information is the PLMN-level system information when acontent of the system information is commonly used or valid to multiplecells within a PLMN area, the cell-level system information is eitherdynamic system information or semi-static system information, thecell-level system information is the dynamic system information when acontent of the secondary system information is frequently changed, thecell-level system information is the semi-static system information whena content of the secondary system information is not frequently changed,the primary system information is transmitted via the first type ofchannel and/or the secondary system information is transmitted via thesecond type of channel, and the first type of channel is a BroadcastChannel (BCH) and the second type of channel is a Downlink SharedChannel (DL-SCH).

It can be also said that this disclosure provide a method of receivingsystem information in a mobile communication system, the methodcomprising: receiving the system information via at least one of a firsttype of channel and a second type of channel, wherein the first type ofchannel is a statically scheduled channel and the second type of channelis a flexibly scheduled channel, the received system information wasclassified by a network entity according to characteristics of thesystem information, the first and second type of channels are transportchannels, the system information was classified into primary systeminformation and secondary system information, the primary systeminformation includes at least one of PLMN information and schedulinginformation of the secondary system information, the system informationwas classified into cell-level system information and PLMN-level systeminformation, the cell-level system information is either dynamic systeminformation or semi-static system information, the primary systeminformation is received via the first type of channel and/or thesecondary system information is received via the second type of channel,and the first type of channel is a Broadcast Channel (BCH) and thesecond type of channel is a Downlink Shared Channel (DL-SCH).

Here, this disclosure may provide a method of transmitting or receivingsystem information utilizing of not only the first and second channelsbut also utilizing of many other different types of channels. Althoughthis disclosure is described in the context of mobile communications,this disclosure may also be used in any wireless communication systemsusing mobile devices, such as PDAs and laptop computers equipped withwireless communication capabilities (i.e. interface). Moreover, the useof certain terms to describe this disclosure is not intended to limitthe scope of this disclosure to a certain type of wireless communicationsystem. This disclosure is also applicable to other wirelesscommunication systems using different air interfaces and/or physicallayers, for example, TDMA, CDMA, FDMA, WCDMA, OFDM, EV-DO, WiMax,Wi-Bro, etc.

The exemplary embodiments may be implemented as a method, apparatus orarticle of manufacture using standard programming and/or engineeringtechniques to produce software, firmware, hardware, or any combinationthereof. The term “article of manufacture” as used herein refers to codeor logic implemented in hardware logic (e.g., an integrated circuitchip, Field Programmable Gate Array (FPGA), Application SpecificIntegrated Circuit (ASIC), etc.) or a computer readable medium (e.g.,magnetic storage medium (e.g., hard disk drives, floppy disks, tape,etc.), optical storage (CD-ROMs, optical disks, etc.), volatile andnon-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs,SRAMs, firmware, programmable logic, etc.).

Code in the computer readable medium may be accessed and executed by aprocessor. The code in which exemplary embodiments are implemented mayfurther be accessible through a transmission media or from a file serverover a network. In such cases, the article of manufacture in which thecode is implemented may comprise a transmission media, such as a networktransmission line, wireless transmission media, signals propagatingthrough space, radio waves, infrared signals, etc. Of course, thoseskilled in the art will recognize that many modifications may be made tothis configuration without departing from the scope of this disclosure,and that the article of manufacture may comprise any information bearingmedium known in the art.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of this disclosure.The appearances of such phrases in various places in the specificationare not necessarily all referring to the same embodiment. Further, whena particular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to affect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

As this disclosure may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, it should also beunderstood that the above-described embodiments are not limited by anyof the details of the foregoing description, unless otherwise specified,but rather should be construed broadly within its spirit and scope asdefined in the appended claims, and therefore all changes andmodifications that fall within the metes and bounds of the claims, orequivalents of such metes and bounds are therefore intended to beembraced by the appended claims.

The invention claimed is:
 1. A method of broadcasting system informationin a Long Term Evolution (LTE) mobile communication system, the methodcomprising: classifying the system information into a first portion anda second portion based on characteristics of the system information, thefirst portion comprising scheduling Master Information Block (MIB)information; broadcasting the first portion of the system informationvia a first type of common transport channel; and transmitting thesecond portion of the system information via a second type of commontransport channel based on the scheduling MIB information, wherein thefirst type of common transport channel is a Broadcast Channel (BCH)which is a statically scheduled common transport channel, wherein thesecond type of common transport channel is a Downlink Shared Channel(DL-SCH) which is a flexibly scheduled common transport channel, andwherein broadcasting the first portion of the system informationcomprises broadcasting the first portion using not more than half of acell bandwidth of the LTE mobile communication system, wherein the cellbandwidth of the LTE mobile communication system equals 20 MHz, andwherein the first portion of the system information is broadcasted usingnot more than half of the 20 MHz cell bandwidth.
 2. The method of claim1, wherein the first portion of the system information is classifiedinto primary system information and the second portion of the systeminformation is secondary system information.
 3. The method of claim 2 1,wherein the primary system MIB information includes at least one ofPublic Land Mobile Network (PLMN) information or the schedulinginformation of the secondary system information.
 4. The method of claim1, wherein the system information is classified into cell-level systeminformation and PLMN-level system information.
 5. The method of claim 4,wherein the system information is the cell-level system information whena content of the system information is used or valid to a specific cell.6. The method of claim 4, wherein the system information is thePLMN-level system information when a content of the system informationis commonly used or valid to multiple cells within a PLMN area.
 7. Themethod of claim 4, wherein the cell-level system information is eitherdynamic system information or semi-static system information.
 8. Themethod of claim 7, wherein the cell-level system information is thedynamic system information when a content of the cell-level systeminformation is frequently changed.
 9. The method of claim 7, wherein thecell-level system information is the semi-static system information whena content of the cell-level system information is not frequentlychanged.
 10. The method of claim 2, wherein at least the primary systeminformation is transmitted via the BCH or the secondary systeminformation is transmitted via the DL-SCH.
 11. A method of receivingsystem information in a Long Term Evolution (LTE) mobile communicationsystem, the method comprising: receiving a broadcast of a first portionof the system information via a first type of common transport channel,the first portion comprising scheduling Master Information Block (MIB)information; and receiving a second portion of the system informationvia a second type of common transport channel based on the schedulingMIB information, wherein the first type of common transport channel is aBroadcast Channel (BCH) which is a statically scheduled common transportchannel, wherein the second type of common transport channel is aDownlink Shared Channel (DL-SCH) which is a flexibly scheduled commontransport channel, and wherein the broadcast of the first portion of thesystem information uses not more than half of a cell bandwidth of theLTE mobile communication system, wherein the cell bandwidth of the LTEmobile communication system equals 20 MHz, and wherein the first portionof the system information is broadcasted using not more than half of the20 MHz cell bandwidth.
 12. The method of claim 11, wherein the firstportion of the system information was classified into is primary systeminformation and the second portion of the system information issecondary system information.
 13. The method of claim 12 11, wherein theprimary system MIB information includes at least one of Public LandMobile Network (PLMN) information or the scheduling information of thesecondary system information.
 14. The method of claim 11, wherein thesystem information was classified into cell-level system information andPLMN-level system information.
 15. The method of claim 14, wherein thecell-level system information is either dynamic system information orsemi-static system information.
 16. The method of claim 12, wherein atleast the primary system information is received via the BCH or thesecondary system information is received via the DL-SCH.
 17. The methodof claim 1, wherein the cell bandwidth of the LTE mobile communicationsystem equals 20 MHz, and wherein the first portion of the systeminformation is broadcast using not more than half of the 20 MHz cellbandwidth.
 18. The method of claim 11, wherein the cell bandwidth of theLTE mobile communication system equals 20 MHz, and wherein the broadcastof the first portion of the system information uses not more than halfof the 20 MHz cell bandwidth.